Check position. Use variable for button time.

main.c

@@ -9,6 +9,9 @@
 #include "usb.h"
 #include "ringbuffer.h"
 #include "uart.h"
+#include "encoder.h"
+
+static const uint32_t button_time = 100;
 
 volatile uint32_t tick = 0;
 RINGBUFFER_STORAGE(usb_to_uart_buf, 64)
@@ -46,10 +49,12 @@ int main(void) {
   uart_setup();
   sys_tick_setup();
   buttons_setup();
+  encoder_setup();
 
   nvic_enable_irq(NVIC_USART3_IRQ);
 
   uint32_t last_tick = tick;
+  int last_pos = 0;
   while (1) {
     /* Handle control messages through the comms CDC */
     char buf[64];
@@ -66,14 +71,24 @@ int main(void) {
           printf("%lu", (unsigned long)adc_bat_voltage());
           break;
         case 'O':
-          buttons_open(15);
+          buttons_open(button_time);
           break;
         case 'C':
-          buttons_close(15);
+          buttons_close(button_time);
+          break;
+        case 'R':
+          printf("pos: %d", encoder_get());
           break;
       }
     }
 
+    int pos = encoder_get();
+    if (pos != last_pos && ringbuffer_empty(comm_out_buf)) {
+      printf("pos: %d", pos);
+      last_pos = pos;
+    }
+
+
     /* Send replies */
     if ((buf_len = ringbuffer_peek(comm_out_buf, &buf[0], sizeof buf))) {
       if (usb_write_cdcacm(ACM_COMM, (void *)buf, buf_len, 1)) {